#!/bin/bash
#shellcheck disable=SC1091
# wslu - Windows 10 linux Subsystem Utility
# Component of Windows 10 linux Subsystem Utility
# <https://github.com/wslutilities/wslu>
# Copyright (C) 2019 Patrick Wu
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

# Current utility
wslu_util_fullpath="$0"
wslu_util_name="${wslu_util_fullpath##*/}"

# Version
wslu_version=VERSIONPLACEHOLDER
wslu_prefix="PREFIXPLACEHOLDER"
wslu_dest_dir="DESTDIRPLACEHOLDER"

# Speed up script by using unicode.
LC_ALL=C
LANG=C

# current state location
wslu_state_dir=${XDG_STATE_HOME:-$HOME/.local/state}/wslu
if [ ! -d "$wslu_state_dir" ]; then
	mkdir -p "$wslu_state_dir"
fi

# prevent bash -x
set +x

bash_version_full=$(bash --version | head -n 1)
bash_version_major=$(echo "$bash_version_full" | cut -d ' ' -f 4 | cut -d '.' -f 1)
bash_version_minor=$(echo "$bash_version_full" | cut -d ' ' -f 4 | cut -d '.' -f 2)

# pipeline content to pipe... if it is wslclip
if [[ "$wslu_util_name" == "wslclip" ]]; then
	if [[ -p /dev/stdin ]]; then
		PIPE=$(cat -)
	fi
fi

# conf handling module
__wsl_conf_read() {
	if [ -f /etc/wsl.conf ]; then
		tmp="$(sed -nr "/^\[${1}\]/ { :l /^${2}[ ]*=/ { s/[^=]*=[ ]*//; p; q;}; n; b l;}" /etc/wsl.conf)"
		if [ -n "$tmp" ]; then
			if [ ${#tmp} -ge 2 ]; then
				if [ "${tmp:0:1}" == '"' ] && [ "${tmp: -1}" == '"' ]; then
					echo "${tmp:1:-1}"
				elif [ "${tmp:0:1}" == "'" ] && [ "${tmp: -1}" == "'" ]; then
					echo "${tmp:1:-1}"
				else
					echo "$tmp"
				fi
			else
				echo "$tmp"
			fi
		fi
	fi
}

# checking interopability
if __wsl_conf_read interop enabled | grep false >/dev/null; then
	 echo -e "WSL Interopability is disabled and WSL Utilities won't work. Please enable it by:
	1. open /etc/wsl.conf using root or equivalent editing permission;
	2. under [interop] section, set enabled to true;
	3. restart your distribution."
	exit 1
elif grep ^disabled /proc/sys/fs/binfmt_misc/WSLInterop >/dev/null; then
	 echo -e "WSL Interopability is temporarily disabled and WSL Utilities won't work. Please enable it by:
	# echo 1 > /proc/sys/fs/binfmt_misc/WSLInterop"
	exit 1
fi

# when --verbose, verbose; when --debug, debug.
#
# They should not exist at the same time, otherwise
# the output would be too messy.
wslu_debug=""
if [ "$1" == "--verbose" ]; then
	echo -e '\e[38;5;202m\033[1m[verbose] Showing verbose output. \033(B\033[m' 1>&2
	shift
	set -x
elif [ "$1" == "--debug" ]; then
	wslu_debug="--debug"
	echo -e '\e[38;5;202m\033[1m[debug:'"${wslu_util_fullpath}"'] Showing debug output. \033(B\033[m' 1>&2
	shift
fi

# variables
## color
black=$(echo -e '\e[30m')
red=$(echo -e '\e[31m')
green=$(echo -e '\e[32m')
brown=$(echo -e '\e[33m')
blue=$(echo -e '\e[34m')
purple=$(echo -e '\e[35m')
cyan=$(echo -e '\e[36m')
yellow=$(echo -e '\e[33m')
white=$(echo -e '\e[37m')
dark_gray=$(echo -e '\e[1;30m')
light_red=$(echo -e '\e[1;31m')
light_green=$(echo -e '\e[1;32m')
light_blue=$(echo -e '\e[1;34m')
light_purple=$(echo -e '\e[1;35m')
light_cyan=$(echo -e '\e[1;36m')
light_gray=$(echo -e '\e[37m')
orange=$(echo -e '\e[38;5;202m')
light_orange=$(echo -e '\e[38;5;214m')
deep_purple=$(echo -e '\e[38;5;140m')
bold=$(echo -e '\033[1m')
reset=$(echo -e '\033(B\033[m')

## indicator
info="${green}[info]${reset}"
input_info="${cyan}[input]${reset}"
error="${red}[error]${reset}"
warn="${orange}[warn]${reset}"

## Windows build number constant
# Windows 10
readonly BN_SPR_CREATORS=15063		#1703, Redstone 2, Creators Update
readonly BN_FAL_CREATORS=16299		#1709, Redstone 3, Fall Creators Update
readonly BN_APR_EIGHTEEN=17134		#1803, Redstone 4, April 2018 Update
readonly BN_OCT_EIGHTEEN=17763		#1809, Redstone 5, October 2018 Update
readonly BN_MAY_NINETEEN=18362		#1903, 19H1, May 2019 Update
readonly BN_NOV_NINETEEN=18363		#1909, 19H2, November 2019 Update
readonly BN_MAY_TWENTYTY=19041		#2004, 20H1, May 2020 Update
readonly BN_OCT_NINETEEN=19042		#20H2, Windows 10 October 2020 Update
readonly BN_MAY_TWNETONE=19043		#21H1, Windows 10 May 2021 Update
readonly BN_NOV_TWENTONE=19044		#21H2, Windows 10 November 2021 Update
# Windows 11
readonly BN_ELEVEN_21H2=22000		#21H2, Windows 11

# echo functions
function debug_echo {
	[ "$wslu_debug" == "--debug" ] && echo "${orange}${bold}[debug:${wslu_util_fullpath}]${reset} $*" 1>&2;
}

function error_echo {
	echo "${error} $1"
	exit "$2"
}

# Check if the version number of bash is greater or equal to 4.4
if [ "$bash_version_major" -lt 4 ] || { [ "$bash_version_major" -eq 4 ] && [ "$bash_version_minor" -lt 4 ]; }; then
	error_echo "Bash version is too old. Please upgrade to 4.4 or later." 1
fi


# source default config
if [ -f "${wslu_dest_dir}${wslu_prefix}/share/wslu/conf" ]; then
	debug_echo "source default setting"
	source "${wslu_dest_dir}${wslu_prefix}/share/wslu/conf"
fi

# source user-defined config
if [ -f "${wslu_dest_dir}${wslu_prefix}/share/wslu/custom.conf" ]; then
	debug_echo "${wslu_dest_dir}${wslu_prefix}/share/wslu/custom.conf found, sourcing"
	source "${wslu_dest_dir}${wslu_prefix}/share/wslu/custom.conf"
fi

if [ -f "${wslu_dest_dir}/etc/wslu/conf" ]; then
	debug_echo "${wslu_dest_dir}/etc/wslu/conf found, sourcing"
	source "${wslu_dest_dir}/etc/wslu/conf"
fi

if [ -f "/etc/wslu/custom.conf" ]; then
	debug_echo "/etc/wslu/custom.conf found, sourcing"
	source "/etc/wslu/custom.conf"
fi

if [ -f "$HOME/.config/wslu/conf" ]; then
	debug_echo "$HOME/.config/wslu/conf found, sourcing"
	source "$HOME/.config/wslu/conf"
fi
if [ -f "$HOME/.wslurc" ]; then
	debug_echo "$HOME/.wslurc found, sourcing"
	source "$HOME/.wslurc"
fi

# functions

function help {
	app_name=$wslu_util_name
	echo -e "$app_name - Part of wslu, a collection of utilities for Windows Subsystem for Linux (WSL)
Usage: $2

For more help for $app_name, please use the command \`man $app_name\` or visit the following site: https://wslutiliti.es/wslu/man/$app_name.html.
For overall help, you can use the command \`man wslu\` or visite the following site: https://wslutiliti.es/wslu."
}

function version {
	echo "wslu v$wslu_version"
}

function double_dash_p {
	echo "${@//\\/\\\\}"
}

function interop_prefix {

	win_location="/mnt/"
	tmp="$(__wsl_conf_read automount root)"
	[ "$tmp" == "" ] || win_location="$tmp"
	[[ "$win_location" =~ ^.*/$ ]] || win_location="$win_location/" # make sure it always end with slash
	unset tmp
	echo "$win_location"

	unset win_location
}

function sysdrive_prefix {
	hard_reset=0
	for pt in "$(interop_prefix)"/*; do
		[[ -e "$pt" ]] || break
		if [ "$(echo "$pt" | wc -l)" -eq 1 ]; then
			if [ -d "$pt/Windows/System32" ]; then
				hard_reset=1
				pt=${pt%/}
				win_location="${pt##*/}"
				break
			fi
		fi 
	done

	if [ $hard_reset -eq 0 ]; then
		win_location="c"
	fi

	echo "$win_location"

	unset win_location
	unset hard_reset
}

function wslu_get_build {
	build=$("$(interop_prefix)$(sysdrive_prefix)"/Windows/System32/reg.exe query "HKLM\\Software\\Microsoft\\Windows NT\\CurrentVersion" /v CurrentBuild | tail -n 2 | head -n 1 | sed -e 's|\r||g')
	echo "${build##* }"
}

function wslu_get_wsl_ver {
	wslutmpbuild="$(( $(wslu_get_build) + 0 ))"
	if [ $wslutmpbuild -ge $BN_MAY_NINETEEN ]; then
		# The environment variable only available in 19H1 or later.
		wslu_distro_regpath=$("$(interop_prefix)$(sysdrive_prefix)"/Windows/System32/reg.exe query "HKCU\\SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Lxss" /s /f DistributionName 2>&1 | sed -e 's|\r||g' | grep -B1 -e "$WSL_DISTRO_NAME$" | head -n1 )
		if "$(interop_prefix)$(sysdrive_prefix)"/Windows/System32/reg.exe query "$wslu_distro_regpath" /v Flags &>/dev/null; then
			wslu_distro_version=$("$(interop_prefix)$(sysdrive_prefix)"/Windows/System32/reg.exe query "$wslu_distro_regpath" /v Flags | tail -n 2 | head -n 1 | sed -e 's|\r||g')
			wslu_distro_version=${wslu_distro_version##* }
			wslu_distro_version_processed=$(( "$(printf "%d\n" "$wslu_distro_version")" / 8 ))
			if [ "$wslu_distro_version_processed" == "1" ]; then
				echo "2"
			elif [ "$wslu_distro_version_processed" == "0" ]; then
				echo "1"
			fi
		else
			echo "1"
		fi
	else
		echo "1"
	fi
}

function chcp_com {
	"$(interop_prefix)$(sysdrive_prefix)"/Windows/System32/chcp.com "$@" >/dev/null
}

function winps_exec {
	debug_echo "winps_exec: called with command $*"
	if [[ "$WSLU_POWERSHELL_CHCP_WORKAROUND" == "true" ]]; then
		wslutmpbuild="$(wslu_get_build)"
		cp="$(cat "${wslu_state_dir}"/oemcp)"
		[ "$wslutmpbuild" -ge $BN_OCT_NINETEEN ] || chcp_com "$cp"
		"$(interop_prefix)$(sysdrive_prefix)"/Windows/System32/WindowsPowerShell/v1.0/powershell.exe -NoProfile -NonInteractive -ExecutionPolicy Bypass -Command "[Console]::OutputEncoding = [System.Text.Encoding]::UTF8; [Console]::InputEncoding = [System.Text.Encoding]::GetEncoding($cp); $*"
		EXIT_STATUS=$?
		[ "$wslutmpbuild" -ge $BN_OCT_NINETEEN ] || chcp_com 65001
		return $EXIT_STATUS
	else
		"$(interop_prefix)$(sysdrive_prefix)"/Windows/System32/WindowsPowerShell/v1.0/powershell.exe -NoProfile -NonInteractive -ExecutionPolicy Bypass -Command "$*"
		EXIT_STATUS=$?
		return $EXIT_STATUS
	fi
}

function cmd_exec {
	debug_echo "cmd_exec: called with command $*"
	"$(interop_prefix)$(sysdrive_prefix)"/Windows/System32/cmd.exe /c "$@"
	EXIT_STATUS=$?
	return $EXIT_STATUS
}

function baseexec_gen {
	debug_echo "baseexec_gen: called"
	wslutmpbuild="$(( $(wslu_get_build) + 0 ))"
	debug_echo "baseexec_gen: winbuild: $wslutmpbuild"
	if [ $wslutmpbuild -ge $BN_MAY_NINETEEN ]; then
		# The environment variable only available in 19H1 or later.
		debug_echo "baseexec_gen: 19H1 or higher"
		wslu_distro_regpath=$("$(interop_prefix)"c/Windows/System32/reg.exe query "HKCU\\SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Lxss" /s /f DistributionName 2>&1 | sed -e 's|\r||g' | grep -B1 -e "$WSL_DISTRO_NAME$" | head -n1 )
		if "$(interop_prefix)$(sysdrive_prefix)"/Windows/System32/reg.exe query "$wslu_distro_regpath" /v PackageFamilyName &>/dev/null; then
			wslu_distro_packagename=$("$(interop_prefix)$(sysdrive_prefix)"/Windows/System32/reg.exe query "$wslu_distro_regpath" /v PackageFamilyName | tail -n 2 | head -n 1 | sed -e 's|\r||g')
			# if it is a store distro
			debug_echo "baseexec_gen: store distro: $wslu_distro_packagename"
			wslu_distro_packagename=${wslu_distro_packagename##* }
			wslu_base_exec_folder_path="$(wslpath "$(winps_exec "[Environment]::GetFolderPath('LocalApplicationData')" | tr -d "\r")\\Microsoft\\WindowsApps\\$wslu_distro_packagename")"
			debug_echo "baseexec_gen: base_exe_folder_path: $wslu_base_exec_folder_path"
			if find "$wslu_base_exec_folder_path" -name "*.exe" -print -quit &>/dev/null; then
				debug_echo "baseexec_gen: found exe in wslu_base_exec_folder_path"
				wslpath -w "$(find "$wslu_base_exec_folder_path" -name "*.exe" -print -quit)" > "${wslu_state_dir}"/baseexec
			else
				debug_echo "baseexec_gen: do not have base exec in the folder; use fallback"
				echo "$(wslpath -w "$(interop_prefix)$(sysdrive_prefix)")\\Windows\\System32\\wsl.exe" > "${wslu_state_dir}"/baseexec
			fi
		else
			debug_echo "baseexec_gen: imported distro"
			# if it is imported distro
			echo "$(wslpath -w "$(interop_prefix)$(sysdrive_prefix)")Windows\\System32\\wsl.exe" > "${wslu_state_dir}"/baseexec
		fi
	else
		debug_echo "baseexec_gen: fallback mode"
		# older version fallback.
		echo "$(wslpath -w "$(interop_prefix)$(sysdrive_prefix)")\\Windows\\System32\\wsl.exe" > "${wslu_state_dir}"/baseexec
	fi
}

function var_gen {
	debug_echo "var_gen: called"
	date +"%s" > "${wslu_state_dir}"/triggered_time

	rm -f "${wslu_state_dir}"/baseexec
	rm -f "${wslu_state_dir}"/oemcp

	# generate oem codepage
	"$(interop_prefix)$(sysdrive_prefix)"/Windows/System32/reg.exe query "HKLM\\SYSTEM\\CurrentControlSet\\Control\\Nls\\CodePage" /v OEMCP 2>&1 | sed -n 3p | sed -e 's|\r||g' | grep -o '[[:digit:]]*' > "${wslu_state_dir}"/oemcp
	# generate base exe location
	baseexec_gen

}

function wslu_function_check {
	# from https://stackoverflow.com/questions/85880/determine-if-a-function-exists-in-bash
	debug_echo "wslu_function_check: called with $*"
	declare -f -F "$1" > /dev/null
	return $?
}

function wslu_file_check {
	debug_echo "wslu_file_check: called with $*"
	should_i_show=""
	[[ "$3" == "?!S" ]] && should_i_show="n"

	if [[ ! -f "$1/$2" ]]; then
		[[ -z "$should_i_show" ]] && echo "${warn} $2 not found in Windows directory. Copying right now..."
		[[ -d "$1" ]] || mkdir "$1"
		if [[ -f "/usr/share/wslu/$2" ]]; then
			cp "/usr/share/wslu/$2" "$1"
			[[ -z "$should_i_show" ]] && echo "${info} $2 copied. Located at \"$1\"."
		else
			[[ -z "$should_i_show" ]] && echo "${error} $2 not found. Failed to copy."
			exit 30
		fi
	fi
}

function wslpy_check {
	debug_echo "wslpy_check"
	if type python3 > /dev/null 2>&1; then
		debug_echo "wslpy_check: python3 installed."
		tmp_wslpy_ver="$(python3 -c "import wslpy; print(wslpy.__version__)" 2>/dev/null)"
		if [[ "$tmp_wslpy_ver" != "" ]]; then
			debug_echo "wslpy_check: wslpy installed."
			older_ver="$(echo -e "$tmp_wslpy_ver\n0.1.0" | sort -n -t. | head -n1)"
			if [[ "$older_ver" == "$tmp_wslpy_ver" ]]; then
				debug_echo "wslpy_check: wslpy installed but a version < 0.1.0 is installed."
				return 1
			else
				debug_echo "wslpy_check: wslpy >= 0.1.0 is installed."
				return
			fi
		else
			debug_echo "wslpy_check: wslpy not installed."
			return 1
		fi
	else
		debug_echo "wslpy_check: python3 not installed."
		return 1
	fi
}


# pre_check to make sure WSL_INTEROP is properly set in WSL2
if [ "$(wslu_get_wsl_ver)" == "2" ] && [ -z "$WSL_INTEROP" ]; then
	for i in $(pstree -np -s $$ | grep -o -E '[0-9]+'); do
		if [[ -e "/run/WSL/${i}_interop" ]]; then
			export WSL_INTEROP=/run/WSL/${i}_interop
		fi
	done
fi

# first run, saving some information
if [ ! -d ~/.config/wslu ]; then
	debug_echo "first run; creating ~/.config/wslu"
	mkdir -p ~/.config/wslu
fi

# This gets tirggered then:
# 1. if it's the first time the script is triggered, i.e.,
#    ${wslu_state_dir}/triggered time
# 2. if update_time is also not present, i.e.,
#    badly installed packages or installed via install script
if [ ! -f "${wslu_state_dir}"/triggered_time ] || [ ! -f /usr/share/wslu/updated_time ]; then
	debug_echo "first run or update_time not present; calling var_gen"
	var_gen
# This gets triggered when:
#    installed time is larger than the last triggered time
elif [ "$(cat "${wslu_state_dir}"/triggered_time)" -lt "$(cat /usr/share/wslu/updated_time)" ]; then
	debug_echo "upgraded package; calling var_gen"
	var_gen
fi

# basic distro detection
distro="$(sed -n -e '/^NAME=.*/p' /etc/os-release | sed -e 's/^NAME=\"//g')"
case $distro in
	*Clear\ Linux*) distro="clear";;
	*Common\ Base\ Linux\ Mariner*) distro="cblm";;
	*Pengwin*) distro="pengwin";;
	*WLinux*) distro="wlinux";;
	Ubuntu*) distro="ubuntu";;
	*Debian*) distro="debian";;
	*Kali*) distro="kali";;
	openSUSE*) distro="opensuse";;
	SLES*) distro="sles";;
	Alpine*) distro="alpine";;
	Arch*) distro="archlinux";;
	*Oracle*) distro="oracle";;
	AlmaLinux*) distro="almalinux";;
	Scientific*) distro="scilinux";;
	*Fedora\ Remix\ for\ WSL*) distro="fedoraremix";;
	*Fedora*) distro="fedora";;
	*Gentoo*) distro="gentoo";;
	*Generic*) [ "fedora" == "$(grep -e "LIKE=" /etc/os-release | sed -e 's/ID_LIKE=//g')" ] && distro="oldfedora" || distro="unknown";;
	*) distro="unknown";;
esac

debug_echo "distro: $distro"
